Add bwatch as a standalone plugin

bitcoin/block.c

@@ -228,16 +228,24 @@ void bitcoin_block_blkid(const struct bitcoin_block *b,
 	*out = b->hdr.hash;
 }
 
-static bool bitcoin_blkid_to_hex(const struct bitcoin_blkid *blockid,
-				 char *hexstr, size_t hexstr_len)
+bool bitcoin_blkid_from_hex(const char *hexstr, size_t hexstr_len,
+			   struct bitcoin_blkid *blkid)
 {
-	struct bitcoin_txid fake_txid;
-	fake_txid.shad = blockid->shad;
-	return bitcoin_txid_to_hex(&fake_txid, hexstr, hexstr_len);
+	if (!hex_decode(hexstr, hexstr_len, blkid, sizeof(*blkid)))
+		return false;
+	reverse_bytes(blkid->shad.sha.u.u8, sizeof(blkid->shad.sha.u.u8));
+	return true;
 }
 
-char *fmt_bitcoin_blkid(const tal_t *ctx,
-			const struct bitcoin_blkid *blkid)
+bool bitcoin_blkid_to_hex(const struct bitcoin_blkid *blkid,
+			 char *hexstr, size_t hexstr_len)
+{
+	struct sha256_double rev = blkid->shad;
+	reverse_bytes(rev.sha.u.u8, sizeof(rev.sha.u.u8));
+	return hex_encode(&rev, sizeof(rev), hexstr, hexstr_len);
+}
+
+char *fmt_bitcoin_blkid(const tal_t *ctx, const struct bitcoin_blkid *blkid)
 {
 	char *hexstr = tal_arr(ctx, char, hex_str_size(sizeof(*blkid)));
 

bitcoin/block.h

@@ -52,6 +52,11 @@ void fromwire_chainparams(const u8 **cursor, size_t *max,
 			  const struct chainparams **chainparams);
 void towire_chainparams(u8 **cursor, const struct chainparams *chainparams);
 
+bool bitcoin_blkid_from_hex(const char *hexstr, size_t hexstr_len,
+			    struct bitcoin_blkid *blkid);
+bool bitcoin_blkid_to_hex(const struct bitcoin_blkid *blkid,
+			  char *hexstr, size_t hexstr_len);
+
 char *fmt_bitcoin_blkid(const tal_t *ctx,
 			const struct bitcoin_blkid *blkid);
 

bitcoin/test/run-bitcoin_block_from_hex.c

@@ -62,15 +62,6 @@ static const char block[] =
 
 STRUCTEQ_DEF(sha256_double, 0, sha);
 
-static bool bitcoin_blkid_from_hex(const char *hexstr, size_t hexstr_len,
-				   struct bitcoin_blkid *blockid)
-{
-	struct bitcoin_txid fake_txid;
-	if (!bitcoin_txid_from_hex(hexstr, hexstr_len, &fake_txid))
-		return false;
-	blockid->shad = fake_txid.shad;
-	return true;
-}
 int main(int argc, const char *argv[])
 {
 	struct bitcoin_blkid prev;

ccan/ccan/json_out/json_out.c

@@ -306,7 +306,7 @@ bool json_out_addstrn(struct json_out *jout,
 	struct json_escape *e;
 
 	if (json_escape_needed(str, len)) {
-		e = json_escape(NULL, str);
+		e = json_escape_len(NULL, str, len);
 		str = e->s;
 		len = strlen(str);
 	} else

common/json_param.c

@@ -478,6 +478,22 @@ struct command_result *param_string_or_array(struct command *cmd, const char *na
 	return param_string(cmd, name, buffer, tok, &(*result)->str);
 }
 
+struct command_result *param_string_array(struct command *cmd, const char *name,
+					  const char *buffer, const jsmntok_t *tok,
+					  const char ***arr)
+{
+	size_t i;
+	const jsmntok_t *s;
+
+	if (tok->type != JSMN_ARRAY)
+		return command_fail_badparam(cmd, name, buffer, tok,
+					     "should be an array");
+	*arr = tal_arr(cmd, const char *, tok->size);
+	json_for_each_arr(i, s, tok)
+		(*arr)[i] = json_strdup(*arr, buffer, s);
+	return NULL;
+}
+
 struct command_result *param_invstring(struct command *cmd, const char *name,
 				       const char * buffer, const jsmntok_t *tok,
 				       const char **str)

common/json_param.h

@@ -206,6 +206,11 @@ struct command_result *param_string_or_array(struct command *cmd, const char *na
 					     const char * buffer, const jsmntok_t *tok,
 					     struct str_or_arr **result);
 
+/* Array of strings */
+struct command_result *param_string_array(struct command *cmd, const char *name,
+					  const char *buffer, const jsmntok_t *tok,
+					  const char ***arr);
+
 /* Extract an invoice string from a generic string, strip the `lightning:`
  * prefix from it if needed. */
 struct command_result *param_invstring(struct command *cmd, const char *name,

common/json_parse.c

@@ -601,6 +601,13 @@ bool json_to_txid(const char *buffer, const jsmntok_t *tok,
 				     tok->end - tok->start, txid);
 }
 
+bool json_to_bitcoin_blkid(const char *buffer, const jsmntok_t *tok,
+			   struct bitcoin_blkid *blkid)
+{
+	return bitcoin_blkid_from_hex(buffer + tok->start,
+				      tok->end - tok->start, blkid);
+}
+
 bool json_to_outpoint(const char *buffer, const jsmntok_t *tok,
 		      struct bitcoin_outpoint *op)
 {

common/json_parse.h

@@ -108,6 +108,10 @@ bool json_to_msat(const char *buffer, const jsmntok_t *tok,
 bool json_to_txid(const char *buffer, const jsmntok_t *tok,
 		  struct bitcoin_txid *txid);
 
+/* Extract a bitcoin blkid from this */
+bool json_to_bitcoin_blkid(const char *buffer, const jsmntok_t *tok,
+			   struct bitcoin_blkid *blkid);
+
 /* Extract a bitcoin outpoint from this */
 bool json_to_outpoint(const char *buffer, const jsmntok_t *tok,
 		      struct bitcoin_outpoint *op);

common/json_parse_simple.c

@@ -2,6 +2,7 @@
 #include "config.h"
 #include <assert.h>
 #include <ccan/mem/mem.h>
+#include <ccan/str/hex/hex.h>
 #include <ccan/tal/str/str.h>
 #include <common/json_parse_simple.h>
 #include <common/utils.h>
@@ -151,6 +152,18 @@ bool json_to_bool(const char *buffer, const jsmntok_t *tok, bool *b)
 	return false;
 }
 
+bool json_hex_to_be32(const char *buffer, const jsmntok_t *tok, be32 *val)
+{
+	return hex_decode(buffer + tok->start, tok->end - tok->start,
+			  val, sizeof(*val));
+}
+
+bool json_hex_to_be64(const char *buffer, const jsmntok_t *tok, be64 *val)
+{
+	return hex_decode(buffer + tok->start, tok->end - tok->start,
+			  val, sizeof(*val));
+}
+
 
 bool json_tok_is_num(const char *buffer, const jsmntok_t *tok)
 {

common/json_parse_simple.h

@@ -2,6 +2,7 @@
 #ifndef LIGHTNING_COMMON_JSON_PARSE_SIMPLE_H
 #define LIGHTNING_COMMON_JSON_PARSE_SIMPLE_H
 #include "config.h"
+#include <ccan/endian/endian.h>
 #include <ccan/short_types/short_types.h>
 #include <ccan/tal/tal.h>
 
@@ -51,6 +52,12 @@ bool json_to_double(const char *buffer, const jsmntok_t *tok, double *num);
 /* Extract boolean from this */
 bool json_to_bool(const char *buffer, const jsmntok_t *tok, bool *b);
 
+/* Extract big-endian 32-bit from hex string (for datastore) */
+bool json_hex_to_be32(const char *buffer, const jsmntok_t *tok, be32 *val);
+
+/* Extract big-endian 64-bit from hex string (for datastore) */
+bool json_hex_to_be64(const char *buffer, const jsmntok_t *tok, be64 *val);
+
 /* Is this a number? [0..9]+ */
 bool json_tok_is_num(const char *buffer, const jsmntok_t *tok);
 

common/json_stream.c

@@ -193,13 +193,22 @@ void json_add_primitive(struct json_stream *js,
 	tal_free_if_taken(val);
 }
 
+void json_add_stringn(struct json_stream *js,
+		      const char *fieldname,
+		      const char *str TAKES,
+		      size_t len)
+{
+	if (json_filter_ok(js->filter, fieldname))
+		json_out_addstrn(js->jout, fieldname, str, len);
+	if (taken(str))
+		tal_free(str);
+}
+
 void json_add_string(struct json_stream *js,
 		     const char *fieldname,
 		     const char *str TAKES)
 {
-	if (json_filter_ok(js->filter, fieldname))
-		json_out_addstr(js->jout, fieldname, str);
-	tal_free_if_taken(str);
+	json_add_stringn(js, fieldname, str, strlen(str));
 }
 
 static char *json_member_direct(struct json_stream *js,
@@ -298,13 +307,6 @@ void json_add_s32(struct json_stream *result, const char *fieldname,
 	json_add_primitive_fmt(result, fieldname, "%d", value);
 }
 
-void json_add_stringn(struct json_stream *result, const char *fieldname,
-		      const char *value TAKES, size_t value_len)
-{
-	json_add_str_fmt(result, fieldname, "%.*s", (int)value_len, value);
-	tal_free_if_taken(value);
-}
-
 void json_add_bool(struct json_stream *result, const char *fieldname, bool value)
 {
 	json_add_primitive(result, fieldname, value ? "true" : "false");
@@ -455,6 +457,15 @@ void json_add_txid(struct json_stream *result, const char *fieldname,
 	json_add_string(result, fieldname, hex);
 }
 
+void json_add_bitcoin_blkid(struct json_stream *result, const char *fieldname,
+			    const struct bitcoin_blkid *blkid)
+{
+	char hex[hex_str_size(sizeof(*blkid))];
+
+	bitcoin_blkid_to_hex(blkid, hex, sizeof(hex));
+	json_add_string(result, fieldname, hex);
+}
+
 void json_add_outpoint(struct json_stream *result, const char *fieldname,
 		       const struct bitcoin_outpoint *out)
 {

common/json_stream.h

@@ -31,6 +31,7 @@ struct short_channel_id;
 struct sha256;
 struct preimage;
 struct bitcoin_tx;
+struct bitcoin_blkid;
 struct wally_psbt;
 struct lease_rates;
 struct wireaddr;
@@ -310,6 +311,10 @@ void json_add_channel_id(struct json_stream *response,
 void json_add_txid(struct json_stream *result, const char *fieldname,
 		   const struct bitcoin_txid *txid);
 
+/* '"fieldname" : <hexrev>' or "<hexrev>" if fieldname is NULL */
+void json_add_bitcoin_blkid(struct json_stream *result, const char *fieldname,
+			    const struct bitcoin_blkid *blkid);
+
 /* '"fieldname" : "txid:n" */
 void json_add_outpoint(struct json_stream *result, const char *fieldname,
 		       const struct bitcoin_outpoint *out);

doc/lightningd-config.5.md

@@ -575,6 +575,15 @@ command, so they invoices can also be paid onchain.
 
   The *name* is an ISO-4217 name (e.g. USD), which will be passed to *currencyrate* to fetch the exchange rate for that currency on each bookkeeper event.  Setting *name* to the empty string is equivalent not setting it.
 
+* **bwatch-poll-interval**=*MILLISECONDS* [plugin `bwatch`]
+
+  Delay between polls for new blocks from `bitcoind` (default: 30000).
+
+* **experimental-bwatch** [plugin `bwatch`]
+
+  Enable the experimental *bwatch* chain watcher.  Without this, the
+  plugin stays loaded but does not poll `bitcoind` or process watches.
+
 ### Networking options
 
 Note that for simple setups, the implicit *autolisten* option does the

plugins/Makefile

@@ -17,6 +17,18 @@ PLUGIN_TXPREPARE_OBJS := $(PLUGIN_TXPREPARE_SRC:.c=.o)
 PLUGIN_BCLI_SRC := plugins/bcli.c
 PLUGIN_BCLI_OBJS := $(PLUGIN_BCLI_SRC:.c=.o)
 
+PLUGIN_BWATCH_SRC := plugins/bwatch/bwatch.c \
+	plugins/bwatch/bwatch_store.c \
+	plugins/bwatch/bwatch_scanner.c \
+	plugins/bwatch/bwatch_interface.c \
+	plugins/bwatch/bwatch_wiregen.c
+PLUGIN_BWATCH_HEADER := plugins/bwatch/bwatch.h \
+	plugins/bwatch/bwatch_store.h \
+	plugins/bwatch/bwatch_scanner.h \
+	plugins/bwatch/bwatch_interface.h \
+	plugins/bwatch/bwatch_wiregen.h
+PLUGIN_BWATCH_OBJS := $(PLUGIN_BWATCH_SRC:.c=.o)
+
 PLUGIN_COMMANDO_SRC := plugins/commando.c
 PLUGIN_COMMANDO_OBJS := $(PLUGIN_COMMANDO_SRC:.c=.o)
 
@@ -82,6 +94,7 @@ PLUGIN_ALL_SRC :=				\
 	$(PLUGIN_AUTOCLEAN_SRC)			\
 	$(PLUGIN_chanbackup_SRC)		\
 	$(PLUGIN_BCLI_SRC)			\
+	$(PLUGIN_BWATCH_SRC)			\
 	$(PLUGIN_COMMANDO_SRC)			\
 	$(PLUGIN_FUNDER_SRC)			\
 	$(PLUGIN_TOPOLOGY_SRC)			\
@@ -102,12 +115,14 @@ PLUGIN_ALL_HEADER :=				\
 	$(PLUGIN_FUNDER_HEADER)			\
 	$(PLUGIN_PAY_LIB_HEADER)		\
 	$(PLUGIN_OFFERS_HEADER)			\
-	$(PLUGIN_SPENDER_HEADER)
+	$(PLUGIN_SPENDER_HEADER)		\
+	$(PLUGIN_BWATCH_HEADER)
 
 C_PLUGINS :=					\
 	plugins/autoclean			\
 	plugins/chanbackup			\
 	plugins/bcli				\
+	plugins/bwatch/bwatch			\
 	plugins/commando			\
 	plugins/funder				\
 	plugins/topology			\
@@ -185,6 +200,13 @@ plugins/exposesecret: $(PLUGIN_EXPOSESECRET_OBJS) $(PLUGIN_LIB_OBJS) libcommon.a
 
 plugins/bcli: $(PLUGIN_BCLI_OBJS) $(PLUGIN_LIB_OBJS) libcommon.a
 
+plugins/bwatch/bwatch.o: $(PLUGIN_BWATCH_HEADER)
+plugins/bwatch/bwatch_store.o: $(PLUGIN_BWATCH_HEADER)
+plugins/bwatch/bwatch_scanner.o: $(PLUGIN_BWATCH_HEADER)
+plugins/bwatch/bwatch_interface.o: $(PLUGIN_BWATCH_HEADER)
+plugins/bwatch/bwatch_wiregen.o: $(PLUGIN_BWATCH_HEADER)
+plugins/bwatch/bwatch: $(PLUGIN_BWATCH_OBJS) $(PLUGIN_LIB_OBJS) libcommon.a
+
 plugins/keysend: $(PLUGIN_KEYSEND_OBJS) $(PLUGIN_LIB_OBJS) $(PLUGIN_PAY_LIB_OBJS) libcommon.a
 $(PLUGIN_KEYSEND_OBJS): $(PLUGIN_PAY_LIB_HEADER) libcommon.a
 

plugins/bkpr/blockheights.c

@@ -98,13 +98,6 @@ u32 find_blockheight(const struct bkpr *bkpr,
 	return e ? e->height : 0;
 }
 
-static bool json_hex_to_be32(const char *buffer, const jsmntok_t *tok,
-			     be32 *val)
-{
-	return hex_decode(buffer + tok->start, tok->end - tok->start,
-			  val, sizeof(*val));
-}
-
 struct blockheights *init_blockheights(const tal_t *ctx,
 				       struct command *init_cmd)
 {

plugins/bkpr/bookkeeper.c

@@ -14,6 +14,7 @@
 #include <common/coin_mvt.h>
 #include <common/iso4217.h>
 #include <common/json_param.h>
+#include <common/json_parse_simple.h>
 #include <common/json_stream.h>
 #include <common/memleak.h>
 #include <common/mkdatastorekey.h>
@@ -1836,13 +1837,6 @@ static const struct plugin_command commands[] = {
 	},
 };
 
-static bool json_hex_to_be64(const char *buffer, const jsmntok_t *tok,
-			     be64 *val)
-{
-	return hex_decode(buffer + tok->start, tok->end - tok->start,
-			  val, sizeof(*val));
-}
-
 static void memleak_scan_currencyrates(struct htable *memtable,
 				       currencymap_t *currency_rates)
 {